export default {
	namespaced:true,
	state:()=>({
		// 购物车的数组，用来存储购物车中每个商品的信息对象
		// 每个商品的信息对象，都包含如下 6 个属性：
		// { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
		cart: JSON.parse(uni.getStorageSync('cart') || '[]'),
	}),
	mutations:{
		addToCart(state, goods){
			const findResult = state.cart.find(x=>x.goods_id === goods.goods_id);
			if(!findResult){
				state.cart.push(goods)
			}
			else{
				findResult.goods_count++
			}
			// 通过 commit 方法，调用 m_cart 命名空间下的 saveToStorage 方法
			this.commit('m_cart/saveToStorage')
		},
		saveToStorage(state){
			uni.setStorageSync('cart', JSON.stringify(state.cart))
		},
		updateGoodsState(state, goods){
			const findResult = state.cart.find(x=>x.goods_id === goods.goods_id);
			if(findResult){
				findResult.goods_state = goods.goods_state;
				
				this.commit('m_cart/saveToStorage');
			}
		},
		//更新商品数量
		updateGoodsCount(state, goods){
			const findResult = state.cart.find(x=>x.goods_id === goods.goods_id);
			if(findResult){
				findResult.goods_count = goods.goods_count;
				
				this.commit('m_cart/saveToStorage');
			}
		},
		//根据Id删除商品
		removeGoodsById(state, goods_id){
			state.cart = state.cart.filter(x=>x.goods_id !== goods_id)
			
			this.commit('m_cart/saveToStorage');
		},
		//更新购物车状态
		updateAllGoodsState(state, newState){
			state.cart.forEach(x=>x.goods_state = newState)
			this.commit('m_cart/saveToStorage');			
		}
		
		
	},
	getters:{
		
		//购物车的总数量
		total(state){
			// let c = 0;
			// state.cart.forEach(x=>c+=x.goods_count);
			// return c
			//改成reduce的写法
			return state.cart.reduce((total, item)=>total+=item.goods_count, 0)
		},
		//已勾选商品的数量
		checkedCount(state){
			return state.cart.filter(x => x.goods_state).reduce((total,item) => total += item.goods_count, 0)
		},
		//已勾选商品的总价格
		checkedGoodsAmount(state){
			return state.cart.filter(x=>x.goods_state).reduce((total, item)=>total+=item.goods_count*item.goods_price, 0).toFixed(2)
		}
	}
}